"One a Day Keeps the Prison Away": Understanding the Experiences of Individuals Convicted of Sexual Offences Receiving Anti-Androgens for the Treatment of Problematic Sexual Arousal

Problematic sexual arousal (PSA) is an umbrella term to describe a range of clinical presentations related to excessive sexual thinking (e.g., sexual preoccupation) and sexual behavior (e.g., hypersexuality). Although such concepts are known to affect sexual recidivism among individuals convicted of sexual offences, PSA is not routinely or directly targeted in offending behavior programs in England and Wales. However, in recent years, there have been moves to incorporate pharmacological interventions for addressing this among people with sexual offence histories. Although some work to understand the experiences of those taking SSRI medication for this purpose has emerged, little is known about the experiences of service users taking anti-androgen medication. In this study, we interviewed all individuals in prison taking anti-androgens for the treatment of problematic sexual arousal following convictions for sexual offences in England at the time of data collection (N = 10). Using a phenomenologically oriented thematic analysis, we established themes pertaining to "Differing needs: Motivations for treatment," "Medication as a risk management strategy," and how the medication helped the men in their pursuit of "Discovering a 'new me'." This work contributes important knowledge to inform the development of ethical and effective prescribing of anti-androgen medication with this population and offer recommendations for both future research and the development of clinical practice.

Efficacy and safety of anti-androgens in the management of polycystic ovary syndrome: a systematic review and meta-analysis of randomised controlled trials

Background

Anti-androgens and combined oral contraceptive pills (COCPs) may mitigate hyperandrogenism-related symptoms of polycystic ovary syndrome (PCOS). However, their efficacy and safety in PCOS remain unclear as previous reviews have focused on non-PCOS populations. To inform the 2023 International Evidence-based Guideline in PCOS, we conducted the first systematic review and meta-analysis investigating the efficacy and safety of anti-androgens in the management of hormonal and clinical features of PCOS.

Methods

We systematically searched MEDLINE, Embase, PsycInfo, All EBM reviews, and CINAHL up to 28th June 2023 for randomised controlled trials (RCTs) examining oral anti-androgen use, alone or in combination with metformin, COCPs, lifestyle, or other interventions, in women of any age, with PCOS diagnosed by Rotterdam, National Institutes of Health or Androgen Excess & PCOS Society criteria, and using a form of contraception. Non-English studies and studies of less than 6 months duration or which used the same anti-androgen regimen in both/all groups were excluded in order to establish efficacy for the clinical outcomes of interest. Three authors screened articles against selection criteria and assessed risk of bias and quality using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) framework. Critical outcomes (prioritised during guideline development for GRADE purposes) included weight, body mass index (BMI), irregular cycles, hirsutism, liver function, and quality of life. Random effects meta-analyses were conducted where appropriate. This study is registered with PROSPERO, CRD42022345640.

Findings

From 1660 studies identified in the search, 27 articles comprising 20 unique studies were included. Of these, 13 studies (n = 961) were pooled in meta-analysis. Seven studies had a high risk of bias, nine moderate and four low. Anti-androgens included finasteride, flutamide, spironolactone, or bicalutamide. In meta-analysis, anti-androgens + lifestyle were superior to metformin + lifestyle for hirsutism (weighted mean difference [WMD] [95% CI]: -1.59 [-3.06, -0.12], p = 0.03; I2 = 74%), SHBG (7.70 nmol/l [0.75, 14.66], p = 0.03; I2 = 0%), fasting insulin and fasting insulin: glucose ratio (-2.11 μU/ml [-3.97, -0.26], p = 0.03; I2 = 0% and -1.12 [-1.44, -0.79], p < 0.0001, I2 = 0%, respectively), but were not superior to placebo + lifestyle for hirsutism (-0.93, [-3.37, 1.51], p = 0.45; I2 = 76%) or SHBG (9.72 nmol/l [-0.71, 20.14], p = 0.07; I2 = 31%). Daily use was more effective for hirsutism than use every three days (-3.48 [-4.58, -2.39], p < 0.0001, I2 = 1%), and resulted in lower androstenedione levels (-0.30 ng/ml [-0.50, -0.10], p = 0.004; I2 = 0%). Combination treatment with anti-androgens + metformin + lifestyle resulted in lower testosterone compared with metformin + lifestyle (-0.29 nmol/l [-0.52, -0.06], p = 0.01; I2 = 61%), but there were no differences in hirsutism when anti-androgens + metformin + lifestyle were compared with either anti-androgens + lifestyle or metformin + lifestyle. In limited meta-analyses (n = 2 trials), combining anti-androgens with COCP resulted in poorer lipid profiles compared with COCP ± placebo, with no differences in other outcomes.

Interpretation

Current evidence does not support the use of anti-androgens preferentially to COCPs to treat hyperandrogenism in PCOS. Anti-androgens could be considered to treat hirsutism in PCOS, where COCPs are contraindicated, poorly tolerated, or present a sub-optimal response after a minimum 6-month period, with consideration of clinical context and individual risk factors and characteristics.

Funding

National Health and Medical Research Council (NHMRC) of Australia Monash University.

Detection of anti-androgenic activity of chemicals in fish studies: a data review

A systematic review was conducted on the sensitivity of fish testing guidelines to detect the anti-androgenic activity of substances. Sequence Alignment to Predict Across Species Susceptibility (SeqAPASS) was used to investigate the conservation of the androgen receptor (AR) between humans and fish, and among fish species recommended in test guidelines. The AR is conserved between fish species and humans (i.e. ligand binding domain [LBD] homology ≥70%) and among the recommended fish species (LBD homology >85%). For model anti-androgens, we evaluated literature data on in vitro anti-androgenic activity in fish-specific receptor-based assays and changes in endpoints indicative of endocrine modulation from in vivo studies. Anti-androgenic activity was most consistently and reliably detected in in vitro and in vivo mechanistic studies with co-exposure to an androgen (spiggin in vitro assay, Rapid Androgen Disruption Activity Reporter [RADAR] Assay, and Androgenised Female Stickleback Screen). Regardless of study design (Fish Short-Term Reproduction Assay [FSTRA], Fish Sexual Development Test [FSDT], partial or full life-cycle tests), or endpoint (vitellogenin, secondary sexual characteristics, gonadal histopathology, sex ratio), there was no consistent evidence for detecting anti-androgenic activity in studies without androgen co-exposure, even for the most potent substances (while less potent substances may induce no (clear) response). Therefore, based on studies without androgen co-exposure (35 FSTRAs and 22 other studies), the other studies (including the FSDT) do not outperform the FSTRA for detecting potent anti-androgenic activity, which if suspected, would be best addressed with a RADAR assay. Overall, fish do not appear particularly sensitive to mammalian anti-androgens.

Clinical characteristics of patients with metastatic castration-resistant prostate cancer after treatment with combined androgen blockade

BACKGROUND

Although the second-generation androgen receptor inhibitors and taxanes have recently been recommended for the initial treatment of metastatic prostate cancer, bicalutamide and flutamide are still used in a large number of cases. Therefore, it is important to elucidate the clinical characteristics of these treated CRPC cases and their sensitivity to the currently used therapeutic agents. We aimed to examine the outcomes of metastatic castration-resistant prostate cancer following combined androgen blockade as initial therapy at our institution.

METHODS

Ninety-four patients who developed metastatic castration-resistant prostate cancer after hormonal treatment with combined nonsteroidal androgen receptor antagonists and continuous androgen deprivation therapy between January 2015 and December 2020 were included. The presence of visceral metastases, duration of efficacy of each treatment, and overall survival after castration-resistant prostate cancer were evaluated.

RESULTS

Patients with a longer duration of castration-resistant prostate cancer tended to have a longer response duration to subsequent enzalutamide administration (p = 0.003). Patients who achieved a 90% reduction in prostate-specific antigen levels with enzalutamide had a significantly better castration-resistant prostate cancer prognosis (p = 0.002). Meanwhile, those with visceral metastases at the time of castration-resistant prostate cancer diagnosis had a significantly poorer prognosis (p < 0.001). A positive correlation was observed between the treatment efficacy of abiraterone and taxanes for castration-resistant prostate cancer.

CONCLUSION

The study provides scientific evidence to support that patients with longer time to castration-resistant prostate cancer are more sensitive to enzalutamide, and the use of abiraterone between docetaxel and cabazitaxel has favorable prognostic impact. These findings provide instrumental evidence that can enable better treatment selection for prostate cancer patients.

Exposure to the pesticides linuron, dimethomorph and imazalil alters steroid hormone profiles and gene expression in developing rat ovaries

Inhibition of androgen signaling during critical stages of ovary development can disrupt folliculogenesis with potential consequences for reproductive function later in life. Many environmental chemicals can inhibit the androgen signaling pathway, which raises the question if developmental exposure to anti-androgenic chemicals can negatively impact female fertility. Here, we report on altered reproductive hormone profiles in prepubertal female rats following developmental exposure to three pesticides with anti-androgenic potential: linuron (25 and 50 mg/kg bw/d), dimethomorph (60 and 180 mg/kg bw/d) and imazalil (8 and 24 mg/kg bw/d). Dams were orally exposed from gestational day 7 (dimethomorph and imazalil) or 13 (linuron) until birth, then until end of dosing at early postnatal life. Linuron and dimethomorph induced dose-related reductions to plasma corticosterone levels, whereas imazalil mainly suppressed gonadotropin levels. In the ovaries, expression levels of target genes were affected by linuron and dimethomorph, suggesting impaired follicle growth. Based on our results, we propose that anti-androgenic chemicals can negatively impact female reproductive development. This highlights a need to integrate data from all levels of the hypothalamic-pituitary-gonadal axis, as well as the hypothalamic-pituitary-adrenal axis, when investigating the potential impact of endocrine disruptors on female reproductive development and function.

Androgen receptor expression in breast cancer: Implications on prognosis and treatment, a brief review

Approximately 70%-85% of breast cancers express androgen receptors (ARs). The role of AR in breast cancer pathogenesis is currently in exploration. Both androgens and anti-androgens have demonstrated variable inhibitory and stimulatory effects in AR-positive breast cancer depending on estrogen receptor and HER2 co-expression. Androgen signaling pathways interact with other critical cellular pathways, such as the PI3K/AKT/mTOR, Ras/Raf/MAPK/ERK, Wnt/β-catenin, and estrogen signaling pathways. Therapeutic exploitation of AR has been the crux of management of prostate cancer for decades. In recent years there has been increasing interest in AR as a novel therapeutic target in breast cancer. There have been many early phase clinical trials evaluating the safety and efficacy of various AR-targeted agents in breast cancer. Some of these studies have shown promising clinical benefits. Studies of biomarkers to identify the patients likely to benefit from AR-targeted therapies are currently in progress. Besides, AR expression may be an important prognostic and predictive marker for breast cancer, which needs to be defined better in future studies.

Targeted nanomedicine modalities for prostate cancer treatment

Prostate cancer (PC) is the second most common cause of death amongst men in the USA. Therapy of PC has been transformed in the past decade by introducing novel therapeutics, advanced functional imaging and diagnostic approaches, next generation sequencing, as well as improved application of existing therapies in localized PC. Treatment of PC at the different stages of the disease may include surgery, androgen deprivation therapy (ADT), chemotherapy and radiation therapy. However, although ADT has proven efficacious in PC treatment, its effectiveness may be temporary, as these tumors frequently develop molecular mechanisms of therapy resistance, which allow them to survive and proliferate even under conditions of testosterone deprivation, inhibition of androgen receptor signaling, or cytotoxic drug treatment. Importantly, ADT was found to induce key alterations which frequently result in the formation of metastatic tumors displaying a therapy refractory phenotype. Hence, to overcome these serious therapeutic impediments, novel PC cell-targeted therapeutic strategies are being developed. These include diverse platforms enabling specific enhanced antitumor drug uptake and increased intracellular accumulation. Studies have shown that these novel treatment modalities lead to enhanced antitumor activity and diminished systemic toxicity due to the use of selective targeting and decreased drug doses. The underlying mechanism of targeting and internalization is based upon the interaction between a selective ligand, conjugated to a drug-loaded nanoparticle or directly to an anti-cancer drug, and a specific plasma membrane biomarker, uniquely overexpressed on the surface of PC cells. Another targeted therapeutic approach is the delivery of unique anti-oncogenic signaling pathway-based therapeutic drugs, which are selectively cytotoxic to PC cells. The current paper reviews PC targeted modalities reported in the past 6 years, and discusses both the advantages and limitations of the various targeted treatment strategies.

Expression variations of two retinoid signaling pathway receptors in the rotifer Brachionus calyciflorus exposed to three endocrine disruptors

Endocrine disruption compounds (EDC) are known to affect reproduction, development, and growth of exposed organisms. Although in vertebrates, EDCs mainly act through steroid receptors (e.g. androgen and estrogen receptors), their absence in many invertebrates suggests the involvement of another biological pathway in endocrine disruption effects. As retinoid signaling pathway is present in almost all Metazoa and its involvement in the endocrine disruption of gastropods (i.e. imposex) has been demonstrated, the present work was devoted to investigating the relative mRNA variations of two retinoid receptors genes, retinoid X receptor (RXR) and retinoid acid receptor (RAR), in the freshwater rotifer Brachionus calyciflorus exposed for 6, 12 and 24 h to flutamide, fenitrothion and cyproterone acetate, three anti-androgens known to disrupt sexual reproduction of Brachionus sp. Results revealed that fenitrothion did not affect the relative mRNA levels RXR and RAR in B. calyciflorus, whereas RXR and RAR mRNA levels could be significantly increased by 2 to 4.5-fold and from 2 to 7-fold after exposure to flutamide and cyproterone acetate, respectively. Moreover, the effects of flutamide and cyproterone acetate were measured from 6 and 12 h of exposure, respectively. Cyproterone acetate caused the highest increase of RXR and RAR mRNA levels, probably due to its progestin activity in addition to its anti-androgenic activity and the potential presence of a membrane-associated progesterone receptor as reported in Brachionus manjavacas. Consequently, although it is still difficult to evaluate the hormonal pathways involved in the endocrine disruption in Brachionus sp., this work suggests that the retinoid signaling pathway appears to be a good starting point to try to elucidate the molecular mechanisms involved in sexual reproductive dysfunction in Brachionidae.

Which chemicals should be grouped together for mixture risk assessments of male reproductive disorders?

There is concern about cumulative exposures to compounds that disrupt male sexual differentiation in foetal life, leading to irreversible effects in adulthood, including declines in semen quality, testes non-descent, malformations of the penis and testis cancer. Traditional chemical-by-chemical risk assessment approaches cannot capture the likely cumulative health risks. Past efforts of focusing on combinations of phthalates, a subgroup of chemicals suspected of contributing to these risks, do not go far enough, as they ignore the contribution of other types of chemicals. With the aim of providing criteria for the inclusion of additional chemicals in mixture risks assessments for male reproductive health, this paper examines the mechanisms of action of various chemicals capable of disrupting male sexual differentiation. An Adverse Outcome Pathway (AOP) network for malformations of the male reproductive system is constructed that includes new findings about the role of disruptions of prostaglandin signalling. This network is used to identify pathways that converge at critical nodal points to produce down-stream adverse effects. From this knowledge, combinations of chemicals with different mechanisms of action are predicted that should result in cumulative effects. These predictions are then mapped against evidence from experimental mixture studies with relevant combinations. From the outcome of this analysis it is concluded that cumulative assessment groups for male reproductive health risks should not only include phthalates but also comprise androgen receptor (AR) antagonists, chemicals capable of disrupting steroid synthesis, InsL3 production, prostaglandin signalling and co-planar polychlorinated dibenzo-dioxins together with other dioxin-like compounds. This list goes far beyond what has been suggested previously. A minimum set of chemicals to be assessed together with phthalates includes pesticides such as vinclozolin, prochloraz, procymidone, linuron, the pain killers paracetamol, aspirin and ibuprofen, pharmaceuticals such as finasteride, ketoconazole, and the lipid-lowering drug simvastin, poly-chlorinated dibenzo-dioxins and other dioxin-like pollutants and phenolics such as bisphenol A and butylparaben. AOP network analyses are essential to overcome difficulties in establishing groupings of chemicals for mixture risk assessments that derive from a narrow focus on mechanisms and modes of action.

Implication of environmental estrogens on breast cancer treatment and progression

Breast cancer is the most diagnosed malignancy among women in the United States. Approximately 70% of breast tumors express estrogen receptor alpha and are deemed ER-positive. ER-positive breast tumors depend upon endogenous estrogens to promote ER-mediated cellular proliferation. Decades of research have led to a fundamental understanding of the role ER signaling in this disease and this knowledge has led to significant advancements in the clinical use of antiestrogens for breast cancer treatment. However, adjuvant breast cancer recurrence and metastatic disease progression due to endocrine therapy resistance are prominent and unresolved issues. The established role that estrogens play in breast cancer pathogenesis explains why some patients initially respond to endocrine therapy but also why a significant number of patients become refractory to antiestrogen treatment. It is been hypothesized that exposure to environmental steroid hormone mimics and/or acquired mechanisms of resistance may explain why endocrine therapy fails in a subset of breast cancer patients. This review will highlight: 1) the relationship between ER signaling and breast cancer pathogenesis, 2) the implication of environmental exposures on steroid hormone regulated processes including breast cancer, and 3) the unresolved issue of endocrine therapy resistance.

Molecular Mechanisms of Enzalutamide Resistance in Prostate Cancer

Purpose of Review

Compensatory mechanisms leading to increased androgen receptor expression and activity after androgen ablation or anti-androgen treatment have been identified in prostate cancer. After hydroxyflutamide and bicalutamide were used in therapy of prostate cancer over many years, novel anti-androgen enzalutamide showed improved clinical activity. However, enzalutamide resistance develops over a certain time period, and molecular mechanisms responsible for this process are heterogeneous.

Research Findings

As with other anti-androgens, these mechanisms include alterations of AR but also may be associated with overexpression of oncogenes which should be targeted by novel therapies. Androgen receptor splice variants have been frequently described in patients who developed enzalutamide resistance. Mutant AR F876L has been detected in patients who are resistant to enzalutamide. Glucocorticoid receptor overexpression has been observed in patient tissues and in pre-clinical models of enzalutamide resistance.

Summary

There is a heterogeneous picture of enzalutamide resistance in prostate cancer and, therefore, the development of appropriate post-enzalutamide treatment remains a challenge.

Metabolite profiles of repeatedly sampled urine from male fathead minnows (Pimephales promelas) contain unique lipid signatures following exposure to anti-androgens

The purpose of this study was twofold. First, we sought to identify candidate markers of exposure to anti-androgens by analyzing endogenous metabolite profiles in the urine of male fathead minnows (mFHM, Pimephales promelas). Based on earlier work, we hypothesized that unidentified lipids in the urine of mFHM were selectively responsive to exposure to androgen receptor antagonists, which is otherwise difficult to confirm using established fish toxicity assays. A second goal was to evaluate the feasibility of non-lethally and repeatedly sampling urine from individual mFHMs over the time course of response to a chemical exposure. Accordingly, we exposed mFHM to the model anti-androgens vinclozolin or flutamide. Urine was collected from each fish at 48hour intervals over the course of a 14day exposure. Parallel experiments were conducted with mFHM exposed to bisphenol A or control water. The frequent handling/sampling regime did not cause apparent adverse effects on the fish. Endogenous metabolite profiling was conducted with gas chromatography-mass spectrometry (GC-MS), which exhibited lower variation for the urinary metabolome than was found in earlier work with nuclear magnetic resonance (NMR) spectroscopy. Specifically, for inter- and intra-individual variations, the median spectrum-wide relative standard deviation (RSD) was 32.6% and 33.3%, respectively, for GC-MS analysis of urine from unexposed mFHM. These results compared favorably with similar measurements of urine from other model species, including the Sprague Dawley rat. In addition, GC-MS allowed us to identify several lipids (e.g., certain saturated fatty acids) in mFHM urine as candidate markers of exposure to androgen receptor antagonists.

Changes in physical functioning and muscle strength in men receiving androgen deprivation therapy for prostate cancer: a controlled comparison

PURPOSE

The purpose of the study is to examine changes in muscle strength and self-reported physical functioning in men receiving androgen deprivation therapy (ADT) for prostate cancer compared to matched controls.

METHODS

Prostate cancer patients scheduled to begin ADT (n = 62) were assessed within 20 days of starting ADT and 6 and 12 months later. Age and geographically matched prostate cancer controls treated with prostatectomy only (n = 86) were assessed at similar time intervals. Grip strength measured upper body strength, the Chair Rise Test measured lower body strength, and the SF-12 Physical Functioning scale measured self-reported physical functioning.

RESULTS

As expected, self-reported physical functioning and upper body muscle strength declined in ADT recipients but remained stable in prostate cancer controls. Contrary to expectations, lower body muscle strength remained stable in ADT recipients but improved in prostate cancer controls. Higher Gleason scores, more medical comorbidities, and less exercise at baseline predicted greater declines in physical functioning in ADT recipients.

CONCLUSIONS

ADT is associated with declines in self-reported physical functioning and upper body muscle strength as well as worse lower body muscle strength relative to prostate cancer controls. These findings should be included in patient education regarding the risks and benefits of ADT. Findings also underscore the importance of conducting research on ways to prevent or reverse declines in physical functioning in this patient population.

Cross-sex hormone therapy for gender dysphoria

PURPOSE

Gender identity is the sense one has of being male or female. Gender dysphoria (GD) refers to the distress caused by the incongruence between gender identity and biological sex in gender-nonconforming individuals. Cross-sex hormone therapy (CHT) aims at easing GD, improving well-being, and quality of life of gender-nonconforming individuals. This can be achieved by inducing and maintaining the desired-sex characteristics in accordance with the specific aspirations and expectations of each individual. Nevertheless, CHT can be associated with potentially serious long-term complications.

METHODS

Here, we review when, how, and how long to prescribe CHT to adult transsexuals as well as what to expect and monitor once it has been initiated.

RESULTS

In recent years, transsexualism has become more and more recognized and depathologized. To manage GD, National and International Standards of Care have been established. Nevertheless, the needs of transgender patients can still be ignored or dismissed. Moreover, some questions remain unanswered because of the lack of specific retrospective or prospective studies on CHT.

CONCLUSION

Education and culturally sensitive training must be supplied to healthcare professionals to overcome the existing issues on GD management and change the perspectives of transsexual people.

Environmental concentrations of anti-androgenic pharmaceuticals do not impact sexual disruption in fish alone or in combination with steroid oestrogens

Sexual disruption in wild fish has been linked to the contamination of river systems with steroid oestrogens, including the pharmaceutical 17α-ethinylestradiol, originating from domestic wastewaters. As analytical chemistry has advanced, more compounds derived from the human use of pharmaceuticals have been identified in the environment and questions have arisen as to whether these additional pharmaceuticals may also impact sexual disruption in fish. Indeed, pharmaceutical anti-androgens have been shown to induce such effects under laboratory conditions. These are of particular interest since anti-androgenic biological activity has been identified in the aquatic environment and is potentially implicated in sexual disruption alone and in combination with steroid oestrogens. Consequently, predictive modelling was employed to determine the concentrations of two anti-androgenic human pharmaceuticals, bicalutamide and cyproterone acetate, in UK sewage effluents and river catchments and their combined impacts on sexual disruption were then assessed in two fish models. Crucially, fish were also exposed to the anti-androgens in combination with steroid oestrogens to determine whether they had any additional impact on oestrogen induced feminisation. Modelling predicted that the anti-androgenic pharmaceuticals were likely to be widespread in UK river catchments. However, their concentrations were not sufficient to induce significant responses in plasma vitellogenin concentrations, secondary sexual characteristics or gross indices in male fathead minnow or intersex in Japanese medaka alone or in combination with steroid oestrogens. However, environmentally relevant mixtures of oestrone, 17β-oestradiol and 17α-ethinylestradiol did induce vitellogenin and intersex, supporting their role in sexual disruption in wild fish populations. Unexpectedly, a male dominated sex ratio (100% in controls) was induced in medaka and the potential cause and implications are briefly discussed, highlighting the potential of non-chemical modes of action on this endpoint.

Differential ligand selectivity of androgen receptors α and β from Murray-Darling rainbowfish (Melanotaenia fluviatilis)

Androgen receptors (ARs) mediate the physiological effects of androgens in vertebrates. In fishes, AR-mediated pathways can be modulated by aquatic contaminants, resulting in the masculinisation of female fish or diminished secondary sex characteristics in males. The Murray-Darling rainbowfish (Melanotaenia fluviatilis) is a small-bodied freshwater teleost used in Australia as a test species for environmental toxicology research. We determined concentration-response profiles for selected agonists and antagonists of rainbowfish ARα and ARβ using transient transactivation assays. For both ARα and ARβ, the order of potency of natural agonists was 11-ketotestosterone (11-KT)>5α-dihydrotestosterone>testosterone>androstenedione. Methyltestosterone was a highly potent agonist of both receptors relative to 11-KT. The relative potency of the veterinary growth-promoting androgen, 17β-trenbolone, varied by more than a factor of 5 between ARα and ARβ. The non-steroidal anti-androgen bicalutamide exhibited high inhibitory potency relative to the structurally related model anti-androgen, flutamide. The inhibitory potency of the agricultural fungicide, vinclozolin, was approximately 1.7-fold relative to flutamide for ARα, but over 20-fold in the case of ARβ. Fluorescent protein tagging of ARs showed that the rainbowfish ARα subtype is constitutively localised to the nucleus, while ARβ is cytoplasmic in the absence of ligand, an observation which agrees with the reported subcellular localisation of AR subtypes from other teleost species. Collectively, these data suggest that M. fluviatilis ARα and ARβ respond differently to environmental AR modulators and that in vivo sensitivity to contaminants may depend on the tissue distribution of the AR subtypes at the time of exposure.

Mixtures of environmentally relevant endocrine disrupting chemicals affect mammary gland development in female and male rats

Estrogenic chemicals are able to alter mammary gland development in female rodents, but little is known on the effects of anti-androgens and mixtures of endocrine disrupting chemicals (EDCs) with dissimilar modes of action. Pregnant rat dams were exposed during gestation and lactation to mixtures of environmentally relevant EDCs with estrogenic, anti-androgenic or dissimilar modes of action (TotalMix) of 100-, 200- or 450-fold high end human intake estimates. Mammary glands of prepubertal and adult female and male offspring were examined. Oestrogens increased mammary outgrowth in prepubertal females and the mRNA level of matrix metalloproteinase-3, which may be a potential biomarker for increased outgrowth. Mixtures of EDCs gave rise to ductal hyperplasia in adult males. Adult female mammary glands of the TotalMix group showed morphological changes possibly reflecting increased prolactin levels. In conclusion both estrogenic and anti-androgenic chemicals given during foetal life and lactation affected mammary glands in the offspring.

Investigating apical adverse effects of four endocrine active substances in the freshwater gastropod Lymnaea stagnalis

The hermaphroditic gastropod Lymnaea stagnalis is proposed as a candidate species for the development of OECD guidelines for testing of the reprotoxicity of chemicals, including endocrine active substances (EASs). Up to now, only a few putative EASs have been tested for their reproductive toxicity in this species. In this study, we investigate the effects of four EASs with different affinities to the vertebrate estrogen and androgen receptors (chlordecone as an estrogen; cyproterone acetate, fenitrothion and vinclozolin as anti-androgens) on the reproduction of L. stagnalis in a 21-day semi-static test. Testosterone and 17α-ethinylestradiol (EE2) were used as the reference compounds. The tested EASs had no significant effect on growth and survival at the tested concentration ranges (ng to μg/L). Classical reproduction endpoints (i.e., oviposition and fecundity) were not responsive to the tested chemicals, except for chlordecone and 17α-ethinylestradiol, which hampered reproduction from 19.6 μg/L and 17.6 μg/L, respectively. The frequency of polyembryonic eggs, used as an additional endpoint, demonstrated the effects of all compounds except EE2. The molecular pathways, which are involved in such reproduction impairments, remain unknown. Our results suggest that egg quality is a more sensitive endpoint as compared to other reproductive endpoints commonly assessed in mollusk toxicity tests.

Methodology for profiling anti-androgen mixtures in river water using multiple passive samplers and bioassay-directed analyses

The identification of endocrine disrupting chemicals in surface waters is challenging as they comprise a variety of structures which are often present at nanomolar concentrations and are temporally highly variable. Hence, a holistic passive sampling approach can be an efficient technique to overcome these limitations. In this study, a combination of 4 different passive samplers used for sampling polar (POCIS Apharm and POCIS Bpesticide) and apolar compounds (LDPE low density polyethylene membranes, and silicone strips) were used to profile anti-androgenic activity present in river water contaminated by a wastewater effluent. Extracts of passive samplers were analysed using HPLC fractionation in combination with an in vitro androgen receptor antagonist screen (YAS). Anti-androgenic activity was detected in extracts from silicone strips and POCIS A/B at (mean ± SD) 1.1 ± 0.1 and 0.55 ± 0.06 mg flutamide standard equivalents/sampler respectively, but was not detected in LDPE sampler extracts. POCIS samplers revealed higher selectivity for more polar anti-androgenic HPLC fractions compared with silicone strips. Over 31 contaminants were identified which showed inhibition of YAS activity and were potential anti-androgens, and these included fungicides, germicides, flame retardants and pharmaceuticals. This study reveals that passive sampling, using a combination of POCIS A and silicone samplers, is a promising tool for screening complex mixture of anti-androgenic contaminants present in surface waters, with the potential to identify new and emerging structures with endocrine disrupting activity.